EPA's Air Quality Guide for Ozone Provides detailed information about what the Air Quality Index means. Helps determine ways to protect your family's health when ozone levels reach the unhealthy range, and ways you can help reduce ozone air pollution.

EPA’s Asthma Web Site EPA's Communities in Action Asthma Initiative is a coordinated effort to reduce the burden of asthma and includes programs to address indoor and outdoor environments that cause, trigger or exacerbate asthma symptoms.

Ozone: Good Up High, Bad Nearby (PDF)(2 pp, 1.3 MB) Ozone acts as a protective layer high above the earth, but it can be harmful to breathe. This publication provides basic information about ground level and high-altitude ozone.

Ozone and Your Health (PDF)(2 pp, 2.5 MB) This short, colorful pamphlet tells who is at risk from exposure to ozone, what health effects are caused by ozone, and simple measures that can be taken to reduce health risk.

Ozone Air Quality Designations Provides information on the process EPA, the states, and the tribes follow to designate areas as "attainment" (meeting) or "nonattainment" (not meeting) the ground level ozone standards

Acid Rain Program Uses a combination of traditional requirements and a market-based cap and trade program to reduce power plant emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2), which contribute to ground level formation.

General Conformity Under the General Conformity Rule, federal agencies must work with State, Tribal and local governments in a nonattainment or maintenance area to ensure that federal actions conform to the air quality plans established in the applicable state or tribal implementation plan.

Regional Transport Rule (1998) Reduces regional emissions of nitrogen oxides (NOx) in 22 states and the District of Columbia, and in turn, reduces the regional transport of ozone.

Section 126 Petitions (1999) In response to comments, EPA made available unit-specific information on heat input and electric generation from large boilers and turbines in the NOX State Implementation Plan (SIP) Call region, including 22 States and the District of Columbia.

The 2004 Clean Air Nonroad Diesel Rule Established emission standards for the engines used in most construction, agricultural, and industrial equipment, and reduces the amount of sulfur allowed in the fuel they use.

Air Quality Criteria Document for Ozone (February 2006): This comprehensive assessment of scientific data about the health and environmental effects of ground level ozone is an important part of EPA’s review of its ozone standards.

NAAQS Standards Chart EPA’s Office of Air Quality Planning and Standards (OAQPS) establishes National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" pollutants.